Ambush
by ScopesMonkey
Summary: The conversation that made Sherlock and Tricia Remsen friends.


**A/N:** I was encouraged to publish this on pain of drastic but unspecified things happening to me if I didn't... so here you go. It's set during "A Mirror Without", right before things go crazy, so about the end of September. I do not own, nor do I profit from. Enjoy!

* * *

"I know you're following me. You're doing a right poor job of it."

Sherlock feigned surprise at the woman speaking to him, glancing down casually, disdainfully, at the short figure just up the aisle from him, with her basket resting on the ground at her feet, her arms crossed over her stomach, her blue eyes evaluating him, blazing and bright.

"I'm not following you," Sherlock replied coolly. "I'm doing the shopping."

In response, and as evidence, he lifted his own basket slightly, which was filled with a motley assortment of whatever food in the small store had caught his attention.

"You never do the shopping," Tricia Remsen retorted.

He selected a can of peas from the shelf and dropped it in the basket, then took another for good measure, letting it join its companion. John could probably figure out something to do with them. He was quite brilliant in the kitchen, when he wanted to be, but lazy, and tended to prefer take away.

Of course, Sherlock himself was just above cooking altogether, except for breakfast. Some concessions had to be made. For John.

"And how would you know my shopping habits?" he enquired, keeping his voice somewhat chilly.

She raised her eyebrows, as if she thought he might be mad, or a touch daft.

"I do talk to John, you know," she replied.

"I know," Sherlock answered. "I've heard him on the phone with you on several occasions."

"And you've accessed his email, I'm sure."

"Only when necessary. He has no business discussing my shopping habits with you."

"Sorry, what shopping habits?" Tricia shot back.

"I've been known to do the grocery shopping from time to time."

"What, twice a year?"

"Perhaps thrice," Sherlock replied.

He was uncertain about this woman, who had reappeared so abruptly in John's life after such an extended absence. Of course, she had been only physically absent, still in Afghanistan until only a few weeks ago, but had maintained contact with John via regular phone calls and emails, and the occasional written letter. Sherlock hadn't really paid much attention to this when John had first moved in, because he had any number of friends who had still been in the service when he'd been pensioned back to London. But he had noticed fairly quickly that one name had come up more in John's email (when Sherlock needed to check it, for purely case-related reasons, of course) or on John's blog.

The first time he'd enquired about her, John wouldn't talk about it at all, clamming up tightly, but upon reflection, it may have been a bad time to ask, since earlier that day there had been reports of several British army vehicles being damaged by IEDs on a road near Kabul and John had slept badly the night before, troubled by almost precognitive nightmares. Sherlock had known this because he'd been up working and had had to dash upstairs, unusually alarmed, to wake John up when his flatmate had begun yelling in his sleep.

But later John had been willing to talk about her, this good friend he'd left behind, another surgeon, someone he missed terribly, someone whose safety he worried over every day.

At first, Sherlock had wondered vaguely if their relationship had been sexual, but John had begun to see Sarah, and nothing in the way he talked about Tricia made Sherlock really suspect that John had romantic feelings for Tricia.

He had yet to properly evaluate what Tricia thought about John.

Which had brought him to this small store in Bloomsbury, ostensibly buying groceries.

"We're nowhere near your flat, why would you bother shopping here?" she continued, keeping a sharp eye on him. Sherlock considered that she was very good at this – he'd had a lifetime of practice evading Mycroft's pointed gaze, but something about the woman's bright blue eyes bored into him, making it impossible to completely elude her.

It was fairly impressive, actually.

"Variety," he replied.

"Right," she snorted, picking up her basket. "What do you want?"

"What do you want?" he asked in return.

"To finish my shopping."

"Then by all means," he said, gesturing to her with his free hand. She gave him another calculating look which he returned – as intelligent as she must be, to be a doctor and an experienced combat surgeon, he was a genius, so his calculating looks must be, by definition, more accurate.

She strode away, up the aisle, and Sherlock turned back to the shelf, wondering why there were so many varieties of the same sorts of canned vegetable. Really, weren't peas all peas? It was a bit baffling, to say the least.

He wondered if he should text John for a list, but that would just alert John as to where he was, and what he was up to. If Tricia hadn't already texted John to ask him what his husband was doing, following her about a grocery store.

* * *

When he paid for the odd collection of foodstuffs he'd settled on, he was not at all surprised to find Tricia waiting for him outside, a reusable grocery bag resting on the sidewalk beside her right leg, her hands bundled into the pockets of her dark blue trench coat. She gave him a look when he emerged, and he returned it with an indecipherable look of his own.

"Now who is following whom?" Sherlock asked.

"I'm clearly not following you," Tricia said. "I'm waiting. There's a distinct difference."

"Ambush?" Sherlock enquired.

"You can _see_ me," she replied, and Sherlock actually fought down a momentary smile, keeping his expression severe. "We're going for coffee."

"I haven't the time," Sherlock sniffed.

"Really? Because I just texted John to find out what you were up to today and he said you were probably at home, making a nuisance of yourself, since you're between cases. I think that qualifies as having time."

He stared at her, trying to debate what his options were, but she'd actually done it – gathered evidence beforehand to trip him up. Despite himself, he was somewhat impressed.

"Very well," he agreed. "Although if the milk goes bad, I shall require you to buy me more."

At this, she said nothing, shouldering her bag, adjusting the strap of her handbag on her other shoulder and then giving an impatient look back at him.

"Coming?" she asked.

He fell into step beside her and noted she matched his long-legged pace without much difficulty, despite the fact that she was nearly a full foot shorter than him.

He wasn't sure what to make of her, this brisk, almost bristly woman, with her shaggy blond hair, slightly darker at the roots, but not dyed, her sharp blue eyes, her quick temper but quicker wit.

The first time he had met her, when John had welcomed her home, she had appraised Sherlock very appreciatively, a distinctly unusual sensation for the consulting detective, then impressed upon him the need to ensure that John did his physio stretches for his recently re-injured left shoulder. Sherlock had been taken aback. He'd been expecting – he wasn't entirely certain what he'd been expecting, when it came to it, but not such obvious immediate admiration of how he looked, of John's choice of partner. Nor such frank admonishment of John. Particularly not in the space of just under one minute.

It was somewhat disconcerting to be reminded that other people had known John longer than he had, and perhaps better, at one time.

Sherlock had no doubts he knew John better than anyone now – understanding people was what he did. Reading them, deciphering their little puzzles, unravelling their motivations. He had found, when applied to John in a more thorough manner, this meant learning more about John than he'd ever even thought there was.

In so many things, John continued to surprise him.

But it had been difficult, if not impossible, to learn everything he would want to know about John's old army friends without them actually being present. Particularly this one. He wished he understood why that was.

There was something about Tricia and John he hadn't yet pinned down.

Oh, not the nature of their relationship, that was obvious. The moment he'd seen them together, it had clicked into place. It had never been sexual, no. Because it was familial. Without being related, they had become siblings.

There was more to it, though, which Sherlock did not quite grasp.

Yet.

Which is why he'd sought Tricia out doing her shopping near her flat in Bloomsbury, which was, admittedly, not the most convenient to his flat, but only a short tube ride away.

And why he hadn't bothered concealing himself when observing her – he did want to speak to her, but wanted her to approach him about it, assume it was her idea, her decision.

She took them to a café a block and a half away and opened the door, almost-but-not-quite letting it go behind her too soon so that Sherlock had to catch it quickly, narrowing his eyes at the back of her head.

Had she done that deliberately? Was she trying to off-balance him? If so, it was not going to work.

He had faced far more dangerous and complex foes than Tricia Remsen, and was not about to be daunted by a one hundred and sixty-three centimetre tall woman who probably weighed a good thirty kilos less than he did, at very least. Even if she had been a soldier and thus was probably a good shot. She wasn't armed, so Sherlock wasn't worried about that, and nor did he really concern himself with the idea that former soldiers were running about shooting people in London.

At least, he corrected himself, they were not doing so unnecessarily.

But he'd never been faced with a friend of John's before, one that John had known before knowing Sherlock himself.

That scarcely mattered, he insisted in the privacy of his own mind.

He wasn't entirely sure he believed himself.

They stood silently in line for coffee and Tricia paid for both of them, which took Sherlock aback somewhat, since she'd made no indications she was going to do so, nor had he expected it. But she didn't say anything, nor did she acknowledge the look he gave her. Instead, she dumped two creamers into her coffee and one sugar, while Sherlock took his habitual two sugars and stirred them in.

Tricia led them back outside, settling them down next to an empty table with disposable cups and an empty muffin wrapper still on it, where someone else was not likely to sit next to them. Sherlock tapped his fingers against his cup and Tricia wrapped her hands around hers. It was slightly chilly, but not quite unpleasantly so, nor cold enough yet for gloves.

"Are you going to tell me what you want?" she enquired after they had sat in silence for a moment, evaluating one another with sharp eyes.

"What makes you think I want anything?" Sherlock replied.

"Good Lord, are you always like this?" Tricia wondered instead of answering.

"Like what?" Sherlock replied coolly.

"Evasive and stubborn?"

"Hardly."

She snorted, lifting her coffee cup to her lips and sipping.

"Mm-hmm, that's absolutely what John's always told me."

Sherlock drummed his fingers against his coffee cup again, then stopped when her eyes darted to his hand, noting the movement.

"John should not be talking to you about me," he said firmly.

Tricia blinked, then gave him a puzzled and suspicious look, as though she were trying to evaluate if he were pulling her leg. Sherlock returned it with a serious and steady glare.

"He _is_ my best mate, you know," she pointed out, as if this would somehow have escaped Sherlock's massive intellectual capabilities.

And, he felt, John was _his_ best friend, as well as husband and partner. Clearly, John could not have more than one best friend. It ran counter to the definition of "best".

Tricia gave him another look, this one less surprised, more knowing.

"You must realize he's been talking to me about you before you knew he'd fallen in love with you."

At this, Sherlock repressed a physical start, narrowing his eyes to cover the shock.

"What?" he demanded.

"What did you imagine?" Tricia said. "That he just woke up one day and realized it? That it made complete sense to him and he immediately understood it? Was that how it worked for you?"

Sherlock didn't reply – in part because she'd hit the nail on the head. It had not been immediately apparent, nor had he initially embraced it. To be frank, he'd been at a loss as to how to react, although he did not need her to know this.

There was no way she could have guessed at the time he'd spent considering it, and the time he'd spent trying to avoid thinking of it altogether, attempting to convince himself – rather unsuccessfully, given how much effort he'd had to invest – that he had been wrong about his assessment of John's behaviour.

The time spent trying to work, hunched over a calligraphic cipher and not seeing it, the time spent pacing the flat below John's old bedroom, arguing, batting really, with himself over what to do, what he thought.

What he felt.

Which, in and of itself, had been difficult enough to admit and accept.

Even John didn't entirely know about that to this day.

Tricia leaned forward, hands curling around her coffee cup again, forearms resting on the table.

"Sherlock, do you actually understand that John has never been interested in another man before?" she asked, blue eyes still fixed on him, but now without any trace of suspicion.

"Yes, of course I understand that," he snapped back.

"No," she said, keeping her eyes trained on him, even when most people would have glanced away, broken the contact for a moment, before looking back. "I know you know this, but do you understand it?"

"What's to understand if I know it?" he sighed. "It's all semantics, there's no genuine difference."

At this, Tricia raised her eyebrows.

"Really?" she asked.

"Yes, clearly," he replied. "And people are too caught up in insisting on defining themselves in terms of their sexuality. It's really rather irrelevant."

Tricia sat back, shifting her right hand so it rested on the plastic cover on her cup, her index finger tapping it absently.

"You're right – that _is_ one way people define themselves. But that's my point. His whole adult life, John's been interested in women. Then he met you. And things changed. It took him awhile to realize it, because why would he be expecting it? And then it took him awhile to understand it, and accept it, because it was new and unexpected and he wasn't even sure if he was feeling what he thought he was feeling or if he was making a mistake or if doing anything about it would muck things up between you two irreparably. He was confused, Sherlock. And he needed to talk it out with someone, not just chase himself round in circles in his own head. This took time. But he _chose_ you. Do you understand that? He could have walked away from it, or ignored it, or convinced himself he was barking mad, but he didn't. He chose to face it, to accept it, because it meant even just the _possibility_ of being with you."

She paused, drawing a breath, but Sherlock interjected before she could continue.

"And does that upset you?" he asked sharply.

Tricia blinked then, drawing back slightly.

"Why should it?" she asked in reply, and he heard nothing but genuine enquiry in her voice, saw nothing but the question in her eyes.

"You were the first person he told," Sherlock observed and saw the confirmation of that in her eyes, which was no surprise – there was no one else Sherlock could think of in whom John would confide something like this initially. "And, as you said, John spent his whole adult life being interested in women."

Tricia nodded, then abruptly sighed, putting a hand to her forehead, leaning forward again slightly.

"Lord, not you, too," she muttered, then continued in a voice that indicated she'd stated this many times before, "John and I weren't shagging and we weren't ever interested in each other."

"I know he wasn't sexually interested in you," Sherlock said. "And that your relationship is familial now, but I've no idea what your own history with him is, of course."

"Ah," Tricia said, looking back up, flashing him a quick grin that was not entirely happy. "So _that's_ why we're here."

"Indeed," Sherlock said.

"Did John ever tell you about my brother?" she asked.

"No," Sherlock said. He hadn't known Tricia had a brother – certainly no brother had been present to welcome her home at the airport. At least, he corrected, no biological brother, because John had been there. She had one other living immediate family member, her father, whose health was too fragile for him to have made the trip to Heathrow, but she'd also been welcomed by two cousins and an elderly aunt.

It had been John, though, that'd she'd hugged first.

"Right," she said, meeting his eyes squarely again. "You do that creepy deduction thing you do so well and tell me about my brother."

Sherlock forbore comment on his skills being labelled a "creepy deduction thing" and studied her, blocking out everything else, the scent of his coffee, the voices surrounding them, the hum of traffic in the near background.

"What is his name?" he asked.

She hesitated.

"Jeremy."

_Ah_, he thought, and everything clicked into place, or almost so.

"He's dead," Sherlock said with certainty. "You hesitated when I asked his name. You wanted to correct my tense. Not _is_ but _was_."

She nodded and her expression was suddenly closed, more defensive, and she pulled back physically, only the smallest bit, but it was there.

"Not recently, given the evenness of your voice when you told me to ask about him. And if it had been recent, you would have come home from Afghanistan earlier, more abruptly, and John would have made certain to tell me. And the welcome home would have been much different in tone, so this was before you went overseas."

She nodded, blue eyes a shade darker.

"Quite some time before, I think. But you're still upset about – angry even. So this wasn't something anyone had been expecting. He wasn't ill, or you'd have had some time, at least, to adjust to the fact that he was going to die. And this kind of anger doesn't last at an illness. No _one_ to be angry with. Something happened to him."

Again, Tricia nodded. This time, her eyes flickered down to the table, fixed firmly on the scratched surface. Her jaw was set, and her eyes were bright, not with unshed tears, but with something else.

Guilt.

Misplaced.

And anger.

Not at herself, at her brother.

Sherlock didn't apologize; she wouldn't want to hear it. She'd asked him to tell her about her brother.

"He killed himself," Sherlock said quietly. Tricia's eyes shot back up to meet his, and she nodded, her jaw still tight, her expression hard.

"Yes," she said. "When we were teenagers. Shot himself. My mother and I found him. We'd been out. Shopping."

And later she'd lost her mother, Sherlock knew, to illness. John had told him as explanation as to why Tricia's mother was not welcoming her home to England. Her mother had died of an extended illness some time ago and her father was in failing health. But no mention of a brother.

So she'd become an only child, abruptly, violently, left bereft of a brother she'd loved – Sherlock could see that quite plainly in her expression – and then, years later, she'd met John.

Who had lost Harry, not in the same way, but it was similar. Where Tricia had lost Jeremy once, fast and irrevocably, John lost Harry every single day, over and over again. She was sober now, but it was always uncertain.

So they'd become friends, but it had quickly become more than that, because they were both missing siblings whose dependability and support they'd never had, that they had been robbed of by death and addiction. In a situation like Afghanistan, working together as surgeons, it must only have made things easier to solidify into a sibling-like relationship.

But there was still something missing.

_Shot_, Sherlock realized. There was more in Tricia's expression at the mention of her brother shooting himself than he would normally expect, even for something so horrific.

One brother had shot himself.

The other had been shot by someone else.

"You were John's surgeon," he said, suddenly understanding. John never talked about it, never mentioned it, and Sherlock had always assumed he hadn't known his surgeon, or didn't remember, or it didn't matter. "You were there when he was shot."

The muscles in Tricia's neck worked, then she forced herself to relax.

"Yes," she said.

"You saved his life." Astonishing how such a short, simple sentence could carry so much weight. For both of them.

"I'd already lost one brother," she said flatly. "I wasn't letting another go, not that easily."

Sherlock nodded once, slowly. He could feel the coffee in the cup beginning to lose heat – it was slightly cooler than it had been, but still hot. But he felt no inclination to break the conversation to drink it right now, as warm and welcoming as it was.

"Do you love him?" Tricia asked.

And that, Sherlock realized suddenly, was why _she_ was here.

Asking him the question Harry had never asked of him, because Harry didn't usually bother to talk to him, and he could count on one hand how many times he'd actually met John's inconsistent, alcoholic sister.

He had his suspicions that Mycroft had had some private conversations with John about Sherlock and had given all sorts of admonishments to not hurt his brother, complete with a list of things he could have done to John if John broke these rules.

Which John would ignore, Sherlock knew, because Mycroft did not get to set the rules for their relationship, and Sherlock knew how to handle John. More or less.

Still, it seemed to be some sort of expected sibling ritual.

Judging by the expression on Tricia's face, which was no longer shuttered, but still somewhat tense, she really did want to know.

"Yes," Sherlock replied simply.

He did.

She evaluated him for a long moment, then her expression suddenly relaxed, a bright smile appearing almost unexpectedly. It cleared her blue eyes, chasing away the shadows the conversation had dragged up, returning the light to them.

"Good," she said, and meant it.

Sherlock extended a hand across the table to her, but she surprised him, pushing herself up and leaning over, giving him a quick, warm kiss on the cheek.

Not just John's friend anymore.

His own, too.

* * *

That evening, Sherlock sat reading on the bed, long legs stretched out and crossed at the ankle, ignoring John while John hunted through his bedside table for something. Idly, Sherlock turned the page, not really invested in the story, but not entirely willing to give up on it yet, either. It may improve, but he was so far unconvinced.

"Sherlock, have you seen my picture of me and Tricia?" John finally asked, pausing in his rummaging of the drawer, glancing over his shoulder at his husband.

"What picture?" Sherlock asked vaguely.

"I had a photo of us from Afghanistan that I always kept here," John replied. "I can't find it."

Sherlock turned away from his book, giving John a feigned look of concern.

"You're keeping pictures of women in your nightstand?" he asked, cocking an eyebrow.

"Oh, shove off," John replied. "It's a photo of a friend, and you know it."

"I know she's your friend, but I don't know the photograph," Sherlock replied.

"Argh, where is it?" John muttered. "It's always here!"

"Did you move it?" Sherlock asked vaguely, returning his attention to his book.

"No," John sighed. "At least, I don't think so. Blast. That was my favourite photo of to the two of us."

"Well, I'm certain it will turn up," Sherlock replied absently, keeping a smile to himself, and not at all thinking of the hidden box he had stored in the closet upstairs, with a carefully folded jumper that had been meant for the trash bin, a small, sealed bag of tea sugar, and now, the picture of John and Tricia stored sensibly in an envelope that rested on top of the old green jumper.


End file.
